Francis Bacon triptych at the Tate

But for the next four months, you can visit Tate Britain and see the three-part work that set a world record for Bacon at auction in New York in May.

The private owner is lending the paintings, inspired by Greek mythology, to the first British retrospective for 23 years.

Although the exhibition will go on to the Prado in Madrid and the Metropolitan Museum in New York, London is the only city where the triptych can be seen.

The loan is one of many from private hands for the exhibition of around 70 masterpieces that marks the centenary of Bacon's birth.

Works depicting the crucifixion from key stages in Bacon's career - including his first published work and the first masterpiece of his maturity - are being shown together for the first time.

The exhibition also includes the three different triptychs of his lover George Dyer, including the one produced in the outpouring of grief that immediately followed Dyer's suicide in 1971.

Another highlight is the first fulllength painting of a pope - one of five in the show - which was thought to have been destroyed by the artist but was found rolled up after his death.

All are being exhibited with the first display in Britain of archive material found in his studio that shed new light on his working methods. It includes crumpled photographs of his friends and lovers including Dyer and Peter Lacy, many splashed with paint.

Chris Stephens, the co-curator, said he hoped the exhibition would show Bacon, who died in 1992, was the father of British Pop in depicting everyday subjects and using photography and the key figure of the immediate post-War.

He was not as violent as people imagined, Dr Stephens said. "His underlying philosophy as an atheist was we have a limited time, we're simply the same as other animals with uncontrollable urges, fears and lust. But he wasn't that nihilistic. He was optimistic and a very warm person. There's something very different about seeing his greatest works in the flesh."

The exhibition is at the heart of a Bacon bonanza this autumn. The Andipa Gallery is showing Bacon graphics, Christie's is selling a portrait-of Bacon by Lucian Freud for an estimated £5 million to £7 million, and Thames and Hudson is publishing Incunabula by Martin Harrison, documenting Bacon's working methods.

Francis Bacon, sponsored by Bank of America, opens on Thursday and runs until 4 January with admission charge.